package com.yiruantong.common.web.filter;

import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.http.HtmlUtil;
import jakarta.servlet.ReadListener;
import jakarta.servlet.ServletInputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletRequestWrapper;
import com.yiruantong.common.core.utils.StringUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

/**
 * XSS过滤处理
 *
 * @author rattan
 */
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
  /**
   * @param request
   */
  public XssHttpServletRequestWrapper(HttpServletRequest request) {
    super(request);
  }

  @Override
  public String[] getParameterValues(String name) {
    String[] values = super.getParameterValues(name);
    if (values != null) {
      int length = values.length;
      String[] escapseValues = new String[length];
      for (int i = 0; i < length; i++) {
        // 防xss攻击和过滤前后空格
        escapseValues[i] = HtmlUtil.cleanHtmlTag(values[i]).trim();
      }
      return escapseValues;
    }
    return super.getParameterValues(name);
  }

  @Override
  public ServletInputStream getInputStream() throws IOException {
    // 非json类型，直接返回
    if (!isJsonRequest()) {
      return super.getInputStream();
    }

    // 为空，直接返回
    String json = StrUtil.str(IoUtil.readBytes(super.getInputStream(), false), StandardCharsets.UTF_8);
    if (StringUtils.isEmpty(json)) {
      return super.getInputStream();
    }

    // xss过滤
    json = HtmlUtil.cleanHtmlTag(json).trim();
    byte[] jsonBytes = json.getBytes(StandardCharsets.UTF_8);
    final ByteArrayInputStream bis = IoUtil.toStream(jsonBytes);
    return new ServletInputStream() {
      @Override
      public boolean isFinished() {
        return true;
      }

      @Override
      public boolean isReady() {
        return true;
      }

      @Override
      public int available() throws IOException {
        return jsonBytes.length;
      }

      @Override
      public void setReadListener(ReadListener readListener) {
      }

      @Override
      public int read() throws IOException {
        return bis.read();
      }
    };
  }

  /**
   * 是否是Json请求
   */
  public boolean isJsonRequest() {
    String header = super.getHeader(HttpHeaders.CONTENT_TYPE);
    return StringUtils.startsWithIgnoreCase(header, MediaType.APPLICATION_JSON_VALUE);
  }
}
